During the producing process of TFT-LCDs, it is necessary to connect the lead wirings on the array substrate (i.e., array substrate lead wirings, including gate lead wirings, data lead wirings, etc) and the lead wirings on the driving chip assembly (i.e., chip lead wirings) to achieve the control over the liquid crystal display. The driving chip assembly may be a chip on film (COF) or a chip on glass substrate (COG), etc.
An open failure at the connection between the driving chip assembly and the array substrate (i.e., the connection position of the driving chip assembly) is a kind of frequent failures and may be classified into three types according to the open positions: 1) the disconnections of the array substrate lead wirings are mainly caused by the dusts during the array process, the crush of the foreign matters during the process of cell formation, water vapor corrosion during the post engineering, etc; 2) the disconnections of chip lead wirings are mainly caused by the scratch by the edges of the thin film driving chip assembly and the glass substrate; and 3) the disconnections of the electric connection position of the chip lead wirings and the array substrate lead wirings are mainly caused by metallic corrosion, dusts, lack of the conductive particles, etc. at the via hole positions. If the various open failures mentioned above cannot be repaired, the liquid crystal panel would become a waste product.
There are methods for repairing open failures in a liquid crystal panel at present. FIG. 1 is a conventional repair structure for the open failure of the pixel area, in which the repair lines 1 for the pixel area enclose the pixel area in a circle, and these repair lines 1 for pixel area are overlapped with both the gate lead wirings 3 and the data lead wirings 2. The gate lead wirings 3 and the data lead wirings 2 are crossed in the pixel area to define the pixel array arranged in a matrix. As shown in FIG. 2, when an open position 17 is on one data lead wiring 2, a welding process can be performed at the overlapped positions of a repair line 1 for pixel area with the data lead wiring 2, such that the data line signals corresponding to the open position can be transferred through the repair line 1 for pixel area to achieve a normal display.
However, the inventors found that all the existing techniques for repairing open failures in a liquid crystal panel cannot be used for repairing open failures of the connection position of the driving chip assembly. Thus the traditional open failure of the connection position of the driving chip assembly cannot be repaired, and once it appears, the product has to be treated as a waste product.